Fix some bugs in test_supervisor.erl

Fixes some tests to catch the messages from child ping_pong_servers so they will not be received by
later tests. Changes the supervisor started in test_count_children to use a generic supervisor
without a child, rather than using the modules start_link which always starts a child
ping_pong_server that sends messages back to the test environment. Fixes the test_ping_ping final
`recieve` to match on a new `Pid4` (which would indicate a restart) rather than `Pid3` that the
monitor just caught the 'DOWN' message for.

Signed-off-by: Winford <[email protected]>

Author: UncleGrumpy

tests/libs/estdlib/test_supervisor.erl

@@ -95,21 +95,24 @@ test_count_children() ->
     [{specs, 0}, {active, 0}, {supervisors, 0}, {workers, 0}] = supervisor:count_children(SupPid),
 
     % Add a worker child and verify counts
-    {ok, _ChildPid} = supervisor:start_child(SupPid, #{
+    {ok, ChildPid} = supervisor:start_child(SupPid, #{
         id => test_worker,
         start => {ping_pong_server, start_link, [self()]},
         restart => permanent,
         shutdown => 5000,
         type => worker
     }),
 
+    % Receive message sent back so it won't be left for another test to receive erroneously.
+    ChildPid = get_and_test_server(),
+
     % Check count_children with one active worker
     [{specs, 1}, {active, 1}, {supervisors, 0}, {workers, 1}] = supervisor:count_children(SupPid),
 
-    % Add a supervisor child and verify counts
+    % Add a supervisor child with no children and verify counts
     {ok, _SupervisorPid} = supervisor:start_child(SupPid, #{
         id => test_supervisor,
-        start => {?MODULE, start_link, [self()]},
+        start => {supervisor, start_link, [?MODULE, {test_no_child, self()}]},
         restart => permanent,
         shutdown => infinity,
         type => supervisor
@@ -234,8 +237,8 @@ test_ping_pong(SupPid) ->
     end,
     no_restart =
         receive
-            {ping_pong_server_ready, Pid3} ->
-                Pid3
+            {ping_pong_server_ready, Pid4} ->
+                Pid4
         after 100 -> no_restart
         end,
     unlink(SupPid),
@@ -317,14 +320,17 @@ test_which_children() ->
     [] = supervisor:which_children(SupPid),
 
     % Add a child and test
-    {ok, _ChildPid} = supervisor:start_child(SupPid, #{
+    {ok, ChildPid} = supervisor:start_child(SupPid, #{
         id => test_child,
         start => {ping_pong_server, start_link, [self()]},
         restart => permanent,
         shutdown => 5000,
         type => worker
     }),
 
+    % Receive message sent back so it won't be left for another test to receive erroneously.
+    ChildPid = get_and_test_server(),
+
     % Check which_children returns the child info
     [{test_child, ChildPid, worker, [ping_pong_server]}] = supervisor:which_children(SupPid),
     true = is_pid(ChildPid),